URINARY FLUORIDE EXCRETION IN 4-YEAR-OLD CHILDREN IN SRI-LANKA AND ENGLAND

Urine was collected over 24 h from children aged 4 years in Sri Lanka and England. Fifty-three children were from Dambulla, Sri Lanka, and 4 4 from Newcastle, England, both localities receiving drinking water co ntaining 0.8-1.1 mgF/l. Urine volume was measured immediately after th e 24-hour collection and samples of the collection from each child wer e frozen for transportation prior to 'blind' analysis in one laborator y for fluoride content. The mean 24-hour urine volumes were 504 ml (SD 198) in Sri Lanka and 449 ml (SD 196) in England (p = 0.17). The mean F concentrations were 1.19 ppm (SD 0.63) in Sri Lanka and 1.02 ppm (S D 0.42) in England (p = 0.12). The mean weights of fluoride excreted w ere 0.55 mg F/day (SD 0.30) in Sri Lanka and 0.42 mgF/day (SD 0.19) in England (p = 0.009). The distributions of weight of fluoride excreted were also dissimilar in shape between the two countries. The extent t o which these small differences in fluoride excretion in urine reflect differences in fluoride intake needs to be investigated.